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Radionuclide Dosimetric Data Sheets

Actinium-223

Summary data

General

Classification

Isotope:  Ac-223
Atomic number (Z):  89
Mass number (A):  223
Neutron number (N):  134

Radioactive decay

Decay modes:  α
Half-life:  2.1 [m]
Decay constant:  5.5012e-03 [1/s]
Daughters:  Fr-219 (99.0%)
Radioactive daughters:  Fr-219

Dosimetric constants

Mean alpha energy:  6.672 [MeV]
Mean electron energy:  0.02536 [MeV]
Mean photon energy:  0.01903 [MeV]
Air kerma rate constant, Γ10:  3.739e-18 [Gy·m2/Bq·s]
Air kerma coefficient, Kair:  3.739e-18 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δwp:  1.073e-12 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δα:  1.069e-12 [Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δβ-,β+,e-:  4.063e-15 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp:  3.049e-15 [Gy·kg/Bq·s]

Dose point kernels (plot)

Dose point kernel source:  Graves, et al. Medical Physics. 2019 Nov.; 46(11):5284-5293.

Note: Bins are spaced every 0.1 mm until a radius of 10 cm, and every 1 mm until a radius of 2 m.

Download tabulated dose point kernel file here:  www.mirdsoft.org/products/MIRDspecs/Ac-223 DPK.csv

Summary spectra (plot)

Spectra source:  ICRP Publication 107: Nuclear Decay Data for Dosimetric Calculations. Ann. ICRP 2008, 38 (3).

Download tabulated summary spectra file here:  www.mirdsoft.org/products/MIRDspecs/Ac-223 Summary Spectrum.csv

 

Tabulated data

Summary spectra (table)

Spectra source:  ICRP Publication 107: Nuclear Decay Data for Dosimetric Calculations. Ann. ICRP 2008, 38 (3).

Note: Radiations with yield < 0.01 are excluded from the table, but are available in the linked *.csv data.

Download tabulated summary spectra file here:  www.mirdsoft.org/products/MIRDspecs/Ac-223 Summary Spectrum.csv

 

Energy [MeV]

Yield [#/nt] if > 0.01

Radiation type

6.06280e-05

8.385e+00

X-ray

2.82466e-03

3.579e-02

X-ray

1.20348e-02

3.511e-02

X-ray

1.48321e-02

2.995e-02

X-ray

8.64861e-02

1.220e-02

X-ray

3.08263e-05

2.297e+00

Auger electron

1.19222e-04

2.368e+00

Auger electron

1.83821e-04

1.364e+00

Auger electron

4.76605e-04

4.829e-01

Auger electron

1.30001e-03

5.546e-02

Auger electron

2.21694e-03

6.632e-01

Auger electron

2.60286e-03

1.077e-01

Auger electron

9.25168e-03

7.745e-02

Auger electron

1.13555e-02

4.555e-01

Conversion electron

1.20931e-02

3.707e-02

Auger electron

1.50000e-02

1.501e-01

Conversion electron

1.70700e-02

1.164e-02

Conversion electron

2.31790e-02

2.840e-02

Conversion electron

2.44290e-02

2.636e-02

Conversion electron

2.61160e-02

2.702e-02

Conversion electron

2.73660e-02

2.517e-02

Conversion electron

3.75055e-02

1.591e-02

Conversion electron

3.87555e-02

1.408e-02

Conversion electron

6.49200e-02

1.985e-02

Conversion electron

7.99500e-02

1.904e-02

Conversion electron

6.47350e+00

3.032e-02

Alpha

6.52937e+00

3.032e-02

Alpha

6.56454e+00

1.340e-01

Alpha

6.64662e+00

4.361e-01

Alpha

6.66135e+00

3.110e-01

Alpha

1.18314e-01

3.032e-02

Alpha recoil

1.19335e-01

3.032e-02

Alpha recoil

1.19978e-01

1.340e-01

Alpha recoil

1.21478e-01

4.361e-01

Alpha recoil

1.21748e-01

3.110e-01

Alpha recoil

 

Useful Links

Isotope decay characteristics are periodically updated as better measurements can be made - changes that may not be reflected on this page. Please see useful links:

National Nuclear Data Center (NNDC):  https://www.nndc.bnl.gov/nudat3/mird/

International Atomic Energy Agency (IAEA) Livechart:  https://www-nds.iaea.org/relnsd/vcharthtml/VChartHTML.html

Reference Links

ICRP Report 107: https://www.icrp.org/publication.asp?id=ICRP%20Publication%20107

Graves et al. Dose Point Kernels: https://doi.org/10.1002/mp.13789

MIRD Decay Schemes 2nd Edition: https://sites.snmmi.org/SNMMI-MAIN/iCore/Store/StoreLayouts/Item_Detail.aspx?iProductCode=0-932004-80-6

 

 

 

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